Cardiac surgery–associated AKI and the risk of progression to end-stage renal disease. A retrospective cohort study

INTRODUCTION: Cardiac surgery-associated acute kidney injury (CSA-AKI) is associated with increased post-operative complication rate and decreased survival. There is limited knowledge regarding the long-term risk of progressing to end-stage renal disease (ESRD) following cardiac surgery. METHODS: We analyzed the association of CSA-AKI and the cumulative incidence of progression to ESRD in a cohort of consecutive non-emergent cardiac surgical patients operated between 2000 and 2016. Peri-operative data were collected prospectively, while survival and ESRD data were collected retrospectively. We compared the risk of progression to ESRD in patients who experienced mild or moderate-to-severe CSA-AKI to those who did not. Secondarily, we analyzed survival in these respective groups of patients. RESULTS: The median survival time was 13.7 years (95% confidence interval [CI] 13.3,14.1), over a median follow-up time of 11.9 years (interquartile range 7.8,16.6) among the 3753 patients included in the study. Mild AKI occurred in 383 (10.2%) patients, and moderate-to-severe AKI in 129 (3.4%) patients. Altogether, 63 patients developed ESRD during follow-up, and the 20-year cumulative incidence of ESRD was 1.8% (CI 1.4%, 2.4%). When compared to patients without AKI, the hazard ratio of progression to ESRD was 2.62 (CI 1.36, 5.06) in patients with mild AKI and 8.56 (CI 4.33, 16.9) in patients with moderate-to-severe AKI. Peri-operative AKI was also associated with worse long-term survival and with more frequent post-operative complications. CONCLUSION: A clinically significant proportion of patients progress to ESRD during a long-term follow-up after cardiac surgery. CSA-AKI is associated with an increased risk of progressing to ESRD.